Pokémon Mystery Dungeon: Gates to Infinity was a Pokémon anime series that was barely watched by any viewers that it got cancelled after just two episodes. A lot of people watched it, but only 277,312 views as of December 23rd at 7:04p Eastern Time countrywide. The two episodes were episode one, "The Dream", and episode two, "The Challenge of Kyurem". However, the anime series ended with a cliffhanger.
Warning! Spoilers ahead! The following below may have content that are in an episode. So you have been warned.
The story in "The Dream" was that a boy was turned into an Oshawott and then a female Pikachu found him lying on the ground in the middle of the forest, then it is possible that they were dating after that. It is not 100% certain but it is likely. So then Pikachu wanted to open a place called Pokémon Paradise in a blank desert wasteland. Then Oshawott offers to help Pikachu complete her paradise dream. Then Azumarrill (or however you spell it) opens the gates to the wasteland. Then Pikachu and Oshawott run into the wasteland.
The story in "The Challenge of Kyurem" (or "The Challenge" for short,) is that Pikachu and Oshawott meet a group of Pokémon with an Umbreon, an Espeon, a Dunsparce, and the legendary Virizion of the Swords of Justice, and follow them to an icy dungeon. Then, Umbreon, Espeon, Dunsparce, Virizion, Pikachu, and Oshawott walk into the dungeon. Then when Virizion walks in, she passes out. Then when Umbreon walks in, he passes out. Then when Dunsparce walks in, he passes out. Then when Pikachu walks in, she passes out. Then when Espeon walks in, she mentions that it is hard to breathe. Then she passes out. Then Oshawott is the only one who stays up because he was originally human. Then Kyurem jumps down and challenges Oshawott to a battle. Oshawott accepts.
Watch "The Dream" on YouTube by clicking/taping here
Watch "The Challenge of Kyurem" on YouTube by clicking/taping here
